I've experimented with brownprints (VDB or Namias) over cyanotype without much success: the blue image usually fades in the brownprint stage almost to invisibility, despite heavily overexposing the cyanotype.
(There's an article about the approach at
AlternativePhotogphy.com)
I wondered who else had tried this technique with success, and what tips they might have to offer?
Hi, pdeeh:
Looks like not many people have tried this combo. I have tried none either together or individually - so I am uniquely qualified to comment (not.)
I do not have much in the way of ideas for alleviating your current problem of cyanotype image (b)leaching out when you apply the VDB chemistry. If I understand it correctly the
prussian blue in the cyanotype (more so in the “old”) process has finite solubility in water. So brushing on the new sensitizer on top is causing the ferric ferrocyanide to re-dissolve. The question is whether after drying the VDB sensitizer, does the blue color come back or does it move around smearing the image and contaminating lighter areas like the highlights. If it is overall loss of density (but not the image definition) then may be there is some chemistry going on between ferric ferro and either the ferric Am citrate or the silver nitrate to form a colorless compound. I am not quite knowledgeable about that.
However, that got me to think (
caution: armchair alternative process about to happen) what happens if you do the opposite, i.e. make the brown print first and then the cyanotype on top. If you do not tone the former, the image silver will react with the potassium ferri to form silver ferro, bleaching the image. This will cause the sensitizer to become deficient in K ferri (depending on how much is used) in the shadows. Now if you had added KBr to the sensitizer, you would end up with a latent image of the VDB with cyano chemistry on top. Then if you simply expose it without any negative, the VDB image with come back together with the cyanotype. Shadows will be mostly silver and the highlights will be mostly prussian blue and everything else in between. You will end up with a two-tone image like the one created by your reference, but in reverse.
I am sure in reality there will be all kinds of details that will in the end doom the above approach (as usually most of my armchair prognostications do.) May be worth a try, or not?
:Niranjan.